Laser online monitoring dynamic cleaning device and cleaning method thereof

Abstract

The invention provides a laser on-line monitoring dynamic cleaning device and a cleaning method thereof. The laser on-line monitoring dynamic cleaning device comprises a thickness detection assembly; the laser cleaning assembly comprises a plurality of laser units; each laser unit comprises a laser, a first reflector, a diaphragm, a second reflector, a beam expander, a laser beam shaper, a dynamic galvanometer and a field lens which are arranged along the output direction of a laser beam; wherein the dynamic galvanometer comprises a plurality of multi-face prisms connected with driving parts, so as to dynamically adjust the incidence angle of a laser beam to the field lens; the device can adapt to different pollution degrees and surface shapes, the consistency of cleaning quality is ensured, the dynamic galvanometer is arranged for dynamic cleaning, it can be ensured that a laser focus is accurately attached to the curved surface of the graphite boat all the time, the cleaning efficiency is high, cleaning is thorough, and overburning or residues caused by uneven energy can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing, and particularly to a laser on-line monitoring dynamic cleaning device and a cleaning method thereof. Background Art

[0002] Most crystalline silicon solar cells use the direct-type PECVD process, i.e., the tube-type PE process, and require the use of a metal boat or a graphite boat as the carrier of the silicon wafer. As the number of uses of the boat body increases, more silicon nitride dust will accumulate in the clamping point gap and the boat wall, seriously affecting the coating uniformity. After the forming process operation is completed, contaminants or residues mainly composed of silicon nitride will often remain on the surface of the graphite boat. As the number of uses of the boat body increases, the long-term attachment of these residues will corrode various types of graphite boats. Therefore, after the boat body is used a certain number of times, the surface silicon carbide needs to be removed.

[0003] Traditional graphite boat cleaning uses hydrofluoric acid pickling for 6 hours, followed by 6 hours of water washing, and finally 10 hours of drying. The disadvantage is that the water washing time is too long and not clean, greatly reducing the service life of the graphite boat and also increasing the production cost. For metal boats, due to the chemical reaction of metals in acid, only manual grinding or sandblasting can be used to solve the problem. Manual grinding has low efficiency and lacks precision, while sandblasting is fast but seriously damages the boat body. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a laser on-line monitoring dynamic cleaning device and a cleaning method thereof, which can adapt to different pollution degrees and surface shapes, ensure the consistency of cleaning quality, and perform dynamic cleaning through a dynamic galvanometer, so as to ensure that the laser focus always accurately fits the curved surface of the graphite boat, with high cleaning efficiency and clean cleaning, and can avoid overburning or residue caused by uneven energy.

[0005] The embodiments of the present invention are achieved by the following technical solutions:

[0006] A laser on-line monitoring dynamic cleaning device includes:

[0007] A thickness detection component, which includes several detection units for real-time detection of the thickness of the graphite boat;

[0008] A laser cleaning component, which includes several laser units; each of the laser units includes a laser, a first reflector, a diaphragm, a second reflector, an expander, a laser beam shaper, a dynamic galvanometer, and a field lens arranged along the output direction of the laser beam;

[0009] Among them, the dynamic galvanometer includes several multi-faceted prisms connected with driving parts to dynamically adjust the angle of the laser beam incident on the field lens;

[0010] The detection unit is electrically connected to several of the laser units.

[0011] According to a preferred embodiment, the dynamic galvanometer includes an X-axis multi-faceted prism connected to an X-axis motor, a Y-axis multi-faceted prism connected to a Y-axis motor, and a Z-axis multi-faceted prism connected to a Z-axis motor, for dynamically adjusting the angle at which the laser beam is incident on the field lens.

[0012] According to a preferred embodiment, the power output end of the X-axis motor is connected to the X-axis multi-faceted prism, and the X-axis multi-faceted prism rotates with the power output end of the X-axis motor as the rotation axis;

[0013] The power output end of the Y-axis motor is connected to the Y-axis multi-faceted prism, and the Y-axis multi-faceted prism rotates with the power output end of the Y-axis motor as the rotation axis;

[0014] The power output end of the Z-axis motor is connected to the Z-axis multi-faceted prism, and the Z-axis multi-faceted prism rotates with the power output end of the Z-axis motor as the rotation axis.

[0015] According to a preferred embodiment, the detection unit is a film thickness detector.

[0016] According to a preferred embodiment, the laser cleaning assembly includes five laser units arranged side by side.

[0017] According to a preferred embodiment, each of the laser units is provided with a dust removal cover and an air knife.

[0018] A cleaning method for a laser on-line monitoring dynamic cleaning device includes the following steps:

[0019] Step S10, select a suitable laser model and parameters, and adjust according to the material and pollution degree of the graphite boat;

[0020] Step S20, use the laser units to output laser beams to scan the surface of the graphite boat, and adjust the laser energy to be able to effectively remove surface contaminants without affecting the essence of the graphite boat substrate; control the scanning speed and related parameters to ensure the uniformity and efficiency of cleaning, and perform cleaning treatment on the graphite boat;

[0021] Step S30, after the cleaning treatment is completed, rinse the surface of the graphite boat with clean water to remove residual contaminants and debris generated by laser ablation;

[0022] Step S40, perform a drying treatment;

[0023] Step S50, perform quality inspection on the cleaned graphite boat to ensure that the cleaned graphite boat meets relevant standards and usage requirements.

[0024] According to a preferred embodiment, the quality inspection process includes surface cleanliness inspection, dimensional accuracy inspection, and physical property inspection.

[0025] According to a preferred embodiment, the frequency range of the laser beam is 1000 - 8000 kHz.

[0026] According to a preferred embodiment, the energy adjustment range of the laser beam is below 2.5 mJ.

[0027] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0028] In the present invention, a dynamic galvanometer is provided to dynamically adjust the emission angle of the laser beam to clean the graphite boat. It can adapt to different pollution degrees and surface shapes, ensuring the consistency of cleaning quality. Through dynamic cleaning with the dynamic galvanometer, it can ensure that the laser focus always accurately fits the curved surface of the graphite boat, with high cleaning efficiency and thorough cleaning. It can avoid overburning or residue caused by uneven energy, and effectively protect the graphite boat. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required for the embodiment will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of a laser on-line monitoring dynamic cleaning device provided by an embodiment of the present invention;

[0031] Figure 2 It is a schematic structural diagram of the dynamic galvanometer provided by an embodiment of the invention;

[0032] Figure 3 It is a top view structural diagram of the laser cleaning component provided by an embodiment of the invention;

[0033] Figure 4 It is a partial three-dimensional structural diagram of the laser cleaning component provided by an embodiment of the invention.

[0034] Reference numerals: 1, detection unit; 2, laser; 3, first reflector; 4, aperture; 5, second reflector; 6, beam expander; 7, laser beam shaper; 8, field lens; 9, dynamic galvanometer; 91, X-axis motor; 92, X-axis multifaceted prism; 93, Y-axis motor; 94, Y-axis multifaceted prism; 95, Z-axis motor; 96, Z-axis multifaceted prism; 10, dust removal cover; 11, air knife; 12, processed surface of battery cell; 13, laser beam. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0036] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0038] Embodiment

[0039] Please refer to Figures 1 to 4 , a laser on-line monitoring dynamic cleaning device, comprising: a thickness detection component, the thickness detection component includes several detection units 1 for real-time detection of the thickness of the graphite boat; a laser cleaning component, the laser cleaning component includes several laser units; each laser unit includes a laser 2, a first reflector 3, a diaphragm 4, a second reflector 5, a beam expander 6, a laser beam shaper 7, a dynamic galvanometer 9, and a field lens 8 arranged along the output direction of the laser beam 13; wherein, the dynamic galvanometer 9 includes several multi-faceted prisms connected with driving members to dynamically adjust the angle of the laser beam 13 incident on the field lens 8; the detection unit 1 is electrically connected to several laser units.

[0040] Preferably, the dynamic galvanometer 9 includes an X-axis multi-faceted prism 92 connected to an X-axis motor 91, a Y-axis multi-faceted prism 94 connected to a Y-axis motor 93, and a Z-axis multi-faceted prism 96 connected to a Z-axis motor 95 to dynamically adjust the angle of the laser beam 13 incident on the field lens 8.

[0041] Preferably, the power output end of the X-axis motor 91 is connected to the X-axis multi-faceted prism 92, and the X-axis multi-faceted prism 92 rotates with the power output end of the X-axis motor 91 as the rotation axis;

[0042] The power output end of the Y-axis motor 93 is connected to the Y-axis multi-faceted prism 94, and the Y-axis multi-faceted prism 94 rotates with the power output end of the Y-axis motor 93 as the rotation axis;

[0043] The power output end of the Z-axis motor 95 is connected to the Z-axis multi-faceted prism 96, and the Z-axis multi-faceted prism 96 rotates with the power output end of the Z-axis motor 95 as the rotation axis.

[0044] Preferably, the detection unit 1 is a film thickness detector.

[0045] Preferably, the laser cleaning assembly includes five laser units arranged side by side.

[0046] Preferably, each laser unit is provided with a dust removal cover 10 and an air knife 11.

[0047] A cleaning method for a laser on-line monitoring dynamic cleaning device includes the following steps:

[0048] Step S10, select a suitable laser 2 model and parameters, and adjust according to the material and pollution degree of the graphite boat;

[0049] Step S20, use the laser beam 13 output by the laser unit to scan the surface of the graphite boat, and adjust the laser energy to be able to effectively remove surface contaminants without affecting the essence of the graphite boat substrate; control the scanning speed and related parameters to ensure the uniformity and efficiency of cleaning, and perform cleaning treatment on the graphite boat;

[0050] Step S30, after the cleaning treatment is completed, rinse the surface of the graphite boat with clean water to remove residual contaminants and debris generated by laser ablation;

[0051] Step S40, perform a drying treatment; natural air drying or drying at a temperature below 50 degrees can be adopted to avoid the influence of too high temperature on the physical properties of the graphite boat;

[0052] Step S50, perform a quality inspection treatment on the cleaned graphite boat to ensure that the cleaned graphite boat meets relevant standards and usage requirements.

[0053] Preferably, the quality inspection treatment includes surface cleanliness inspection, dimensional accuracy inspection and physical property inspection.

[0054] Preferably, the frequency range of the laser beam 13 is 1000 - 8000 khz.

[0055] Preferably, the energy adjustment range of the laser beam 13 is below 2.5 mj.

[0056] The working principle of the present invention:

[0057] In the present invention, a dynamic galvanometer 9 is provided to dynamically adjust the emission angle of the laser beam 13 to clean the graphite boat. It can adapt to different pollution degrees and surface shapes, ensure the consistency of cleaning quality. Through dynamic cleaning with the dynamic galvanometer 9, it can ensure that the laser focus always accurately fits the curved surface of the graphite boat, with high cleaning efficiency and thorough cleaning. It can avoid overburning or residue caused by uneven energy, and effectively protect the graphite boat.

[0058] In this embodiment, after outputting laser beam 13 from laser 2, it passes sequentially through first reflector 3, aperture 4, second reflector 5, beam expander 6, laser beam shaper 7, dynamic galvanometer 9, and field mirror 8. In dynamic galvanometer 9, the power output end of X-axis motor 91 can be connected to the facets of X-axis polygonal prism 92, the power output end of Y-axis motor 93 is connected to the facets of Y-axis polygonal prism 94, and the power output end of Z-axis motor 95 is connected to the facets of Z-axis polygonal prism 96, thereby adjusting the output movement speed and path of laser beam 13. X-axis polygonal prism 92, Y-axis polygonal prism 94, and Z-axis polygonal prism 96 can be selected from a hexagonal prism, an octagonal prism, or a hexadecanoid prism, depending on the actual situation; for example, X-axis polygonal prism 92 and Y-axis polygonal prism 94 can be hexagonal prisms, while Z-axis polygonal prism 96 can be an octagonal prism. The X-axis polygonal prism 92 , the Y-axis polygonal prism 94 , and the Z-axis polygonal prism 96 may all be octahedral prisms.

[0059] Based on the actual needs of the graphite boat, five laser units can be installed side by side to simultaneously clean the graphite boat. Each dust hood 10 is connected to the dust collector through an independent pipeline. Each laser position is equipped with a separate dust hood 10 and air knife 11. Five lasers are equipped with five dust hoods 10. A customized high-volume ion air knife 11 is installed opposite the suction port of each dust hood 10 to assist in dust removal, effectively removing the plasma and silicon nitride smoke generated by laser processing, and helping to optimize the laser process.

[0060] In this embodiment, five detection units 1 are used, and each laser unit is provided with a detection unit 1. The detection unit 1 can select a film thickness detector, which detects the thickness of the silicon nitride film online and calls the corresponding laser cleaning pattern accordingly. The dynamic galvanometer 9 is used to adjust the focus and cooperate with the detection of the film thickness detector to complete dynamic cleaning. The detection unit 1 can scan the surface of the graphite boat in real time, identify the surface morphology of the graphite boat and the residual state of silicon nitride, distribution and complex geometric structure, and dynamically adjust the laser parameters (such as energy, focus position, power, frequency, scanning path) to ensure that the cleaning range accurately covers the target area, ensure the uniformity and consistency of cleaning, and avoid damaging the substrate. To avoid over-cleaning or under-cleaning, the film thickness detector can provide real-time feedback, and the laser cleaning component can accurately determine the cleaning end point, reducing substrate damage caused by excessive cleaning or process failure caused by insufficient cleaning.

[0061] In this embodiment, the cleaning component is provided with a dynamic galvanometer 9, which can automatically generate a high-speed scanning path in cooperation with the laser 2 to adapt to the porous, multi-layer and special-shaped structures of the graphite boat. The dynamic galvanometer 9 can dynamically adjust the laser incident angle to solve the problem of shadow occlusion under the traditional fixed optical path (such as cleaning the vertical hole wall). In this embodiment, the field lens 8 is of the model F535. Using this focal length, the deflection speed of the laser beam 13 will be 120 m / s, and the cleaning process effect can achieve an accuracy of 0.05 μm. In this embodiment, the film thickness detector and the dynamic focusing of the laser cleaning component are synchronously controlled to ensure that the laser focus always accurately fits the curved surface of the graphite boat (including deep holes and narrow slits), avoiding overburning or residue caused by uneven energy. A micron-level positioning accuracy is achieved, and the positioning accuracy can reach within ±5 μm, and micron-level pollutants (such as nanoparticles attached to graphite pores) can be accurately cleaned. In addition, the dynamic galvanometer 9 can adjust the spot overlap rate to achieve uniform energy distribution and avoid local overheating damage to the graphite substrate.

[0062] High-frequency and high-energy pulsed laser cleaning can be selected. For example, a high-energy laser beam with an output energy of 1 mj can be used for cleaning (and it is not limited to a 1 mj high-energy laser beam, and a high-energy laser beam above 2.5 mj can be selected), in combination with a high-frequency pulsed laser 2 (such as 4000 kHz, etc.). The pulse superposition can quickly remove pollutants, and deep cleaning can be completed in a single scan. mainly using the infrared pulsed laser solution (using the infrared laser 2). The laser solution can achieve processing rectangular spots and strip spots, and can also be customized according to application needs. The minimum range of the spot is from 15*15 um to 2000*200 mm spots. The main red laser 2 solution (using the infrared laser 2); a green laser 2 can also be selected. The wavelength band of the green laser 2 is between 700-1080 nm, and it is also compatible with ultraviolet and green lasers 2: This equipment is compatible with pulsed lasers or continuous lasers, and is also compatible with laser beam splitters. The laser 2 has a power feedback function, and the graphite boat cleaning process from PERC, TOPCON, HJT, and XBC can all be used. In this embodiment, it has low latency and high synchrony, stable mechanical inertia, and after the rotation speed is constant, the scanning path and time are highly predictable, and it is easy to synchronize with external signals, making it suitable for applications with high requirements for timing accuracy. It has wide spectral compatibility. Using the dynamic galvanometer 9, the laser beam 13 deflects quickly, greatly shortening the moving time of the cleaning path. Compared with the ordinary galvanometer system, the cleaning efficiency of this embodiment is improved. In this embodiment, the main cleaning range is the silicon nitride film layer on the surface of the graphite boat, and it is not limited to the silicon nitride film layer. Such as Figure 2As shown, the output path of the cleaning laser beam 13 first passes through the X-axis multi-faceted prism 92 on the X-axis motor 91, and then passes through the Y-axis multi-faceted prism 94 on the Y-axis motor 93 and the Z-axis multi-faceted prism 96 on the Z-axis motor 95. The arrow direction above the X-axis motor 91 is the flipping direction of its power output end, and the arrow direction on the left side of the Y-axis motor 93 is the flipping direction of its power output end. The power output end of the Z-axis motor 95 is arranged longitudinally to drive the Z-axis multi-faceted prism 96 to flip with the longitudinally arranged power output end of the Z-axis motor 95 as the rotation axis. In addition, the laser beam wavelength can also be selected as a laser beam in the range of 266 - 540 nm.

[0063] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. An on-line laser monitoring dynamic cleaning device, characterized in that, Comprising: A thickness detection component, which includes several detection units for real-time detection of the thickness of the graphite boat; A laser cleaning component, which includes several laser units; each of the laser units includes a laser, a first mirror, a diaphragm, a second mirror, a beam expander, a laser beam shaper, a dynamic galvanometer, and a field lens arranged along the output direction of the laser beam; Wherein, the dynamic galvanometer includes several multi-faceted prisms connected with driving parts to dynamically adjust the angle of the laser beam incident on the field lens; The detection unit is electrically connected to several of the laser units.

2. The laser on-line monitoring dynamic cleaning device according to claim 1, characterized in that The dynamic galvanometer includes an X-axis multi-faceted prism connected with an X-axis motor, a Y-axis multi-faceted prism connected with a Y-axis motor, and a Z-axis multi-faceted prism connected with a Z-axis motor to dynamically adjust the angle of the laser beam incident on the field lens.

3. The laser on-line monitoring dynamic cleaning device according to claim 2, characterized in that The power output end of the X-axis motor is connected to the X-axis multi-faceted prism, and the X-axis multi-faceted prism rotates with the power output end of the X-axis motor as the rotation axis; The power output end of the Y-axis motor is connected to the Y-axis multi-faceted prism, and the Y-axis multi-faceted prism rotates with the power output end of the Y-axis motor as the rotation axis; The power output end of the Z-axis motor is connected to the Z-axis multi-faceted prism, and the Z-axis multi-faceted prism rotates with the power output end of the Z-axis motor as the rotation axis.

4. The laser on-line monitoring dynamic cleaning device according to claim 1, characterized in that The detection unit is a film thickness detector.

5. The laser on-line monitoring dynamic cleaning device according to claim 1, characterized in that The laser cleaning component includes five laser units arranged side by side.

6. The laser on-line monitoring dynamic cleaning device according to claim 5, characterized in that Each of the laser units is provided with a dust removal cover and an air knife.

7. The cleaning method of the laser on-line monitoring dynamic cleaning device according to claim 1, characterized in that Including the following steps: Step S10, select a suitable laser model and parameters, and adjust according to the material and pollution degree of the graphite boat; Step S20, use the laser unit to output a laser beam to scan the surface of the graphite boat, and adjust the laser energy to be able to effectively remove surface pollutants without affecting the essence of the graphite boat substrate; control the scanning speed and related parameters to ensure the uniformity and efficiency of cleaning, and perform cleaning treatment on the graphite boat; Step S30, after the cleaning treatment is completed, rinse the surface of the graphite boat with clean water to remove residual pollutants and debris generated by laser ablation; Step S40, perform a drying treatment; Step S50, perform a quality inspection treatment on the cleaned graphite boat to ensure that the cleaned graphite boat meets relevant standards and usage requirements.

8. The laser on-line monitoring dynamic cleaning device and its cleaning method according to claim 7, characterized in that The quality inspection treatment includes surface cleanliness inspection, dimensional accuracy inspection, and physical property inspection.

9. The laser on-line monitoring dynamic cleaning device and its cleaning method according to claim 7, characterized in that The frequency range of the laser beam is 1000 - 8000 khz.

10. The laser on-line monitoring dynamic cleaning device and its cleaning method according to claim 7, characterized in that the energy adjustment range of the laser beam is below 2.5 mj.

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